We won't. Over 80% of oil we pull out of the ground is burned for energy, and we are switching to alternatives at a rate that should have us fully transitioned before we run out.

And thank god, too. We can only pull up a quarter of our proven reserves before hitting 2 degrees warming (the Paris agreement). We hit 3 degrees warming (where the Pentagon says wars start over food) when we pull up a third of proven reserves.

I work in cleantech, and people used to wonder if oil would die at a high price (due to lack of supply) or low price (due to low demand). Nowadays everyone knows it will die at a low price. Also, here's my favorite climate change joke, "They say we won't act until it's too late...Luckily, it's too late!"

https://en.wikipedia.org/wiki/Carbon_bubble